In recent years, attempts to search a molecule that exhibits a specific interaction with a particular molecule using a technique based on intermolecular interactions, or research to investigate intermolecular interactions in detail, has been actively conducted. This is specifically represented by research wherein one molecule of the combination of small molecule-small molecule, small molecule-large molecule, or large molecule-large molecule is immobilized onto a solid phase carrier and the interaction between the two molecules is measured, or research wherein a desired target (a molecule that exhibits a specific interaction with a molecule immobilized onto a solid phase carrier) is purified on the basis thereof. As examples of various techniques based on intermolecular interactions, 1) target research using an affinity resin for the latter case, and 2) a method that applies surface plasmon resonance (Surface Plasmon Resonanse: SPR) for the former case, are known well. As examples of 1), the discovery of FKBP proteins, which bind to the immunosuppressant FK506 (FK506 binding proteins) using an affinity resin by Professor Schreiber in 1989 (discovery of FKBP12 as a protein that binds to FK506 in cells, Nature, 341, 758, 1989), the subsequently done discovery of calcineurin inhibitory action in the pharmacological action mechanism of FK506 by an FK506-FKBP complex (Cell, 66, 807-815, 1991), the discovery of HDAC as a target protein for the anticancer agent Trapoxin (Science, 272, 408, 1996) and the like are known well. Also, as an example of 2), BIACORE (trade name), which employs a gold foil as a solid phase carrier and enables an extensive investigation of an interaction between a compound or a protein and the like and a protein and the like that specifically interacts therewith, is known well.
However, to date, in the above-described techniques, the presence of a nonspecific intermolecular interaction that hampers the selection and purification of a desired molecule based on a specific intermolecular interaction has been posing such problems as 1) in target search using an affinity resin, a nonspecific protein that masks a specific protein during analysis of a protein bound to an affinity resin using SDS gel and the like exists and makes the detection of the specific protein difficult, or 2) in analysis using BIACORE and the like, the presence of a peak resulting from major nonspecific protein adsorption makes the distinguishing of a peak due to specific protein binding. Although these have empirically been considered as being caused by the solid phase carrier, which is an important basic technology, specifically by a surface property of the solid phase carrier, it remains yet to be known clearly which property is the causal factor for a nonspecific interaction, and how to efficiently suppress such a nonspecific intermolecular interaction. For example, some resins such as TentaGel (Fluka Company, Cat. No=86364) have a PEG spacer, are chemically and physically stable, and are also used as resins for affinity chromatography (e.g., Thorpe D S, Walle S., Combinatorial chemistry defines general properties of linkers for the optimal display of peptide ligands for binding soluble protein targets to TentaGel microscopic beads, Biochem Biophys Res Commun 2000 Mar. 16; 269(2):591-5), but basic technologies such as those concerning the identity of the structure that contributes to suppression of a nonspecific interaction and the way of the contribution remain unknown, and there is no sufficient information on to which extent the nonspecific interaction is suppressed or whether or not these resins serve well as affinity resins.
As such PEG spacers, TentaGel, which is described above, and ArgoGel (Argonaut Company) are commercially available. Their structures are as follows

Also, resins comprising a sugar derivative having hydrophilic nature (for example, AffiGel (AffiGel; Bio-Rad Company, Cat. No=153-2401), a Sepharose derivative (Pharmacia Company, ECH Sepharose 4B, Cat. No=17-0571-01) and the like are known) exhibit minor nonspecific intermolecular interactions, but they are physically and chemically unstable because of their identity as sugar derivatives and their use is limited.
If it is possible to artificially suppress nonspecific interactions in the above-described techniques based on intermolecular interactions, it is considered that the necessity of determining whether the results obtained are due to specific protein binding or nonspecific protein adsorption will be obviated, the frequency of research interruption due to the substantial inability to differentiate both thereof will decrease, and the consumption of protein and the like used will be significantly reduced, so that significant cost reductions in terms of time and labor, and the like will increase the applicability of these techniques.
It is an object of the present invention to provide a method of eliminating or suppressing a nonspecific interaction that hampers the analysis of intermolecular interactions on a solid phase carrier, and it is another object to provide a method of purifying and analyzing a molecule that exhibits a specific interaction with a molecule immobilized onto a solid phase carrier using the method described above.